Solid phase affinity binding assays remain among the most versatile and rapid methods for detection of chemical and biological analytes from fluid samples. However, field deployment and point-of-care use of these diagnostic assays have historically been impractical because of the cost of instrumentation and test devices, complicated operation parameters and protocols, and lack of methods for robust storage of biological reagents, the degradation of which leads to poor assay performance.
Microfluidic systems offer solutions to many of these problems. Microfluidic systems and methods of use have been described in detail (Verpoorte, E., Electrophoresis, 2002 23(5), 677-712; Lichtenberg, J., et al., Talanta, 2002. 56(2),233-266; Beebe, D.J., et al., Annual Review of Biomedical Engineering, 2002,4, 261-286; Wang, J., Electrophoresis, 2002, 23(5), 713-718; Becker, H. and L.E. Locascio, Talanta, 2002, 56(2), 267-287; Chovan, T. and A. Guttman, Trends in Biotechnology, 2002. 20(3), 116-122; Becker, H. and C. Gartner, Electrophoresis, 2000, 21(1), 12-26; McDonald, J.C., et al., Electrophoresis, 2000, 21(1), 27-40; Weigl, B.H. and P. Yager, Science, 1999, 283, 346-347; and Shoji, S., Topics in Current Chemistry 1998, 194:163-188; U.S. Pat. Nos. 5,932,100; 5,922,210; 5,747,349; 5,972,710; 5,748,827; 5,726,751; 5,726,404; 5,716,852; 6,159,739; 5,971,158; 5,974,867; 6,007,775; 6,221,677; 5,948,684; 6,067,157; 6,482,306; 6,408,884; 6,415,821; and U.S. Patent Application Nos. 09/703,764 filed Nov. 11, 2000; 09/724,308, filed Nov. 28, 2000; 09/675,550, filed Sep. 27, 2000; 09/863,835, filed May 22, 2001; 09/428,839, filed Oct. 28, 1999; 09/723,823, filed Nov. 28, 2000; 09/503,563, filed Feb. 14, 2000; 09/574,797, filed May 19, 2000; 09/579,666, filed May 26, 2000; and 09/956,467, filed Sep. 18, 2001; all of which are incorporated herein in their entirety to the extent not inconsistent herewith).
Microfluidic systems for use in analyte detection in fluid streams have been studied extensively (e.g. U.S. Pat. Nos. 5,747,349; 5,716,852; 6,007,775; 5,984,684; and U.S. Patent Application No. 09/503,563 filed Feb. 14, 2000; Ser. No. 09/574,797, filed May 19, 2000; Ser. No. 09/863,835, filed May 22, 2000; and Ser. No. 09/724,308, filed Nov. 28, 2000). One fluid-phase analyte detection system utilizes methods for the solid-state storage and preservation of assay reagents in a microfluidic device, negating the need for multiple reagent sources external to the detection device (U.S. Pat. No. 6,007,775, incorporated herein in its entirety, to the extent not inconsistent herewith). Methods and devices for the electrokinetic control or transport of molecules in a microfluidic channel using electrophoresis, isoelectric focusing, and transverse electrophoresis have also been studied (e.g. Harrison, D. J., et al., Sensors and Actuators B: Chemical, 10(2), 107-116; and U.S. Patent Application No. 09/579,666 filed May 26, 2000).
Design of microfluidic systems using laminate technology allows multichannel analysis and the formation of 3-dimensional microfluidic systems of varying degrees of complexity (Jandik, P. et al. Journal of Chromatography A, 2002, 954: 33-40; Cabrera, C. (2002) “Microfluidic Electrochemical Flow Cells: Design, Fabrication, and Characterization”, Thesis, 2002 Department of Bioengineering. Seattle, University of Washington; Cabrera, C. R., et al. Analytical Chemistry, 2001, 73(3), 658-666; Holl, M., et at., “Design of a Microfluidic Electrochemical Flow Cell”, Electrophoresis, 2000 (submitted); Holl, M. R., et al., “Microfluidic device and methods for continuous-flow transverse electrokinetic separations”, Electrophoresis (submitted); Yager, P., et al., “Design of Microfluidic Sample Preconditioning Systems for Detection of Biological Agents in Environmental Samples”, SPIE, Santa Clara, CA; Yager, P., et al., “Analytical Devices Based on Transverse Transport in Microchannels”; Micro Total Analysis Systems 2000, University of Twente, the Netherlands, Kluwer Academic Publishers; Anderson; McDonald, J.C. and Whitesides, G.M., Accounts of Chemical Research, 35(7), 491-499; and McDonald, J.C., et at., Electrophoresis, 21, 27-40; all of which are incorporated herein in their entirety, to the extent not inconsistent herewith).
Solid phase microfluidic affinity binding assays have also been explored for their use with surface plasmon resonance (SPR) technologies to detect analyte binding within a microfluidic device (Jung, L. S., et al. Sensors and Actuators, 1999, 54,137-144; Lyon, L.A., et al. Sensors and Actuators B, 1999, 54, 118-124; Naimushin, A. N., et al., “Detection of Staphylococcus Aureus Enterotoxin B at Femtomolar Levels with a Miniature Integrated Two-channel Surface Plasmon Resonance (SPR) Sensor”, Biosensors & Bioelectronics, 2002, 17:573-584; Place, J. F., et at., Biosensors, 1985, 1, 321-353, all of which are incorporated herein in their entirety to the extent not inconsistent herewith). Other SPR sensing devices have also been described for single or multiple analyte detection (U.S. Pat. Nos. 5,815,278; 5,822,073; 5,991,048; 5,858,799; and U.S. Patent Application Nos. 09/566,772 filed May 8, 2000; 60/1 32,893 filed May 6,1999; 60/1 32,895 filed May 6,1999; and 60/132,894 filed May 6,1999, all of which are incorporated herein in their entirety to the extent not inconsistent herewith).
It is often desirable to detect multiple analytes in parallel in a solid phase affinity binding assay. This parallel detection often involves complex protocols for the deposition and/or patterning of capture molecules on the binding surface. Such assays often require extensive development efforts for determining, for example, the optimum concentration of capture molecules bound to the solid phase.
There is a long felt need in the art of biological and chemical assays for a simple, easy-to-use, practical, inexpensive, compact, portable, versatile, and inexpensive device for performing quantitative bioassays in a variety of testing conditions, from controlled hospital and clinical environments to the often-extreme environments experienced by armed-forces personnel. Ideally, such devices perform parallel analysis of multiple analytes and require minimal development effort for determining optimal assay parameters.